Extraction and carrier mediated transport of urea using noncyclic receptors through liquid membrane systems

Abstract

Extraction and carrier mediated transport through bulk liquid membrane and supported liquid membrane systems have wide applications in separation technology. This paper highlights the use of six noncyclic receptors (podands) having variations in chain length and end group for the removal of urea using liquid membrane system. These receptors R1, R2, R3, R4, R5, R6 are diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, diethylene glycol dibenzoate, diethylene glycol, triethylene glycol and tetraethylene glycol respectively. The sequence of extraction and transport of urea by BLM system using various receptors is R2 > R3 > R1 > R4 > R5 > R6 and R6 ≈ R3 > R5 > R4 > R1 > R2 respectively. Receptor R2 containing butyl end group is best extractant while receptor R6 with flexible backbone is best carrier and this carrier efficiency is used to remove urea using BLM system from the feed phase by recyclization process up to 88.16%. The experimental results influenced by concentration of receptors and urea. Effect of time was also studied. Keywords: Liquid-liquid extraction, Bulk liquid membrane (BLM) and supported liquid membrane (SLM) transport system, Hydrophobicity, Podands, Recyclization